[PATCH] RISC-V: KVM: Fix comments in kvm_riscv_vcpu_isa_disable_allowed

[Andrew Jones]

On Thu, Feb 20, 2025 at 07:49:05AM +0000, Chao Du wrote:
> The comments for EXT_SVADE are opposite with the codes. Fix it to avoid
> confusion.
> 
> Signed-off-by: Chao Du <duchao at eswincomputing.com>
> ---
>  arch/riscv/kvm/vcpu_onereg.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c
> index f6d27b59c641..6df41794e346 100644
> --- a/arch/riscv/kvm/vcpu_onereg.c
> +++ b/arch/riscv/kvm/vcpu_onereg.c
> @@ -203,7 +203,7 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
>  	case KVM_RISCV_ISA_EXT_SVADE:
>  		/*
>  		 * The henvcfg.ADUE is read-only zero if menvcfg.ADUE is zero.
> -		 * Svade is not allowed to disable when the platform use Svade.
> +		 * Svade is allowed to disable when the platform use Svade.
>  		 */

It was correct (but confusing) before this change. When
arch_has_hw_pte_young() returns true, that means we can use
SVADU (which is !SVADE). If we don't have SVADU, then we must
be using SVADE, and therefore can't disable it.

How about

/*
 * The henvcfg.ADUE is read-only zero if menvcfg.ADUE is zero.
 * Svade can't be disabled unless we support Svadu.
 */

Thanks,
drew

>  		return arch_has_hw_pte_young();
>  	default:
> -- 
> 2.34.1
> 
> 
> -- 
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